Light-conducting devices have a broad range of applications in optics, for example in laser optics. An exemplary application is the deflection of linearly arranged light beams.
Generally, optical deflection devices cause light beams which are incident onto the deflection device at an incident angle different from 0° and 90° with respect to an optical axis of the deflection device to be deflected in a plane defined by the optical axis and the incident direction, for example in such a way that the direction of the deflected light beam also includes the incident angle with the optical axis, so that the incident beam and the emergent beam include twice the incident angle. Many optical elements are suitable to deflect light beams. Mirrors and prisms are examples for an optical deflection device.
Prisms are transparent bodies having two parallel base sides in the shape of triangles, trapezoids or parallelograms and at least three rectangular sides perpendicularly adjacent to each of the two base sides. At least one of the rectangular sides is not perpendicularly adjacent to the other sides.
Transparent cuboids with a refractive index greater than 1 can also serve for the beam deflection.
A typical application field of light-conducting devices is the beam shaping in order to improve the beam quality of a light beam generated by a laser bar. In order to make available diode lasers with higher performance, several laser emitters are arranged in a first direction (slow axis) parallel to the active layer and combined into a laser component which is referred to as a laser bar. The beam generated by the bar has a significantly poorer beam quality in the first direction than in a second direction (fast axis) perpendicular to the active layer. The reason therefore is that the beam diameter is larger by orders of magnitude in the first direction than in the second direction. In fact, the beam quality is the inverse beam quality factor M2. The beam quality factor M2 indicates the divergence angle of a real laser beam compared to the divergence angle of an ideal Gaussian beam with an identical (waist) diameter. The divergence angle of the resulting laser beam is smaller in the first direction than in the second direction. By changing the beam diameter in the first and the second direction while maintaining the divergences, the beam can be shaped such that the beam qualities are equalized. The direction of emission is usually perpendicular to the first and second direction.
Thus, the German published patent application DE 10 2009 031 046 A1 proposes a laser optics for beam shaping laser light emitted in a plane by means of semiconductor or diode lasers which comprises a plate fan. Several plates of the plate fan are arranged offset in the direction perpendicular to their surface sides, wherein the plates comprise a planar narrow plate side for the beam entry and an opposite further planar narrow plate side for the beam exit, respectively.
U.S. Pat. No. 6,377,410 B1, US 2005/0068633 A1, WO 2014/026713 A1 and DE 10 2008 033 358 A1 also relate to beam shaping.